METHOD AND APPARATUS FOR CORRELATING NAMESERVER IPV6 AND IPV4 ADDRESSES

摘要

Nameserver addresses are correlated in a multi-tier name server hierarchy comprising a first level authority for a domain, and one or more second level authorities to which the first level authority delegates with respect to a particular sub-domain associated with the domain. Preferably, the first level authority is IPv4-based and at least one second level authority is IPv6-based. The first level authority responds to a request issued by a client caching nameserver (a “CCNS”) and returns an answer that includes both IPv4 and IPv6 authorities for the domain. The CCNS is located at an IPv4 source address that is passed along to the first level authority with the CCNS request. The first level authority encodes the CCNS IPv4 source address in the IPv6 destination address of at least one IPv6 authority. Then, when the CCNS then makes a follow-on IPv6 request (with respect to the sub-domain) directed to the IPv6 authority, the IPv6 authority knows both the IPv6 address of the CCNS (as well as its IPv4 address. The IPv6 authority maintains the IPv4-IPv6 correlation. Over time, the IPv6 authority builds up a database of these CCNS IPv6-IPv4 associations.